Authority versus Persuasion

This paper studies a principal's trade-off between using persuasion versus using interpersonal authority to get the agent to 'do the right thing' from the principal's perspective (when the principal and agent openly disagree on the right course of action). It shows that persuasion and authority are complements at low levels of effectiveness but substitutes at high levels. Furthermore, the principal will rely more on persuasion when agent motivation is more important for the execution of the project, when the agent has strong intrinsic or extrinsic incentives, and, for a wide range of settings, when the principal is more confident about the right course of action.

Culture Clash: The Costs and Benefits of Homogeneity

This paper develops an economic theory of the costs and benefits of corporate culture -- in the sense of shared beliefs and values -- in order to study the effects of 'culture clash' in mergers and acquisitions. I first use a simple analytical framework to show that shared beliefs lead to more delegation, less monitoring, higher utility (or satisfaction), higher execution effort (or motivation), faster coordination, less influence activities, and more communication, but also to less experimentation and less information collection. When two firms that are each internally homogenous but different from each other, merge, the above results translate to specific predictions how the change in homogeneity will affect firm behavior. The paper's predictions can also serve more in general as a test for the theory of culture as homogeneity of beliefs.

Portable, High-Bandwidth Frequency-Domain Photon Migration Instrument for Tissue Spectroscopy

We describe a novel frequency-domain photon migration instrument employing direct diode laser modulation and avalanche photodiode detection, which is capable of noninvasively determinating the optical properties of biological tissues in near real time. An infinite medium diffusion model was used to extract absorption and transport scattering coefficients from 300-kHz to 800-MHz photon-density wave phase data. Optical properties measured in tissue-simulating solutions at 670 nm agreed to within 10% of those expected

A High-Bandwidth Frequency-Domain Photon Migration Instrument for Clinical Use

We have developed a high-bandwidth frequency-domain photon migration (FDPM) instrument which is capable of noninvasively determining the optical properties of biological tissues in near-real-time. This portable, inexpensive, diode-based instrument is unique in the sense that we employ direct diode laser modulation and avalanche photodiode detection. Diffusion models were used to extract the optical properties (absorption and transport scattering coefficients)of tissue-simulating solutions.from the 300 kHz to I GHz photon density wave data

Metabolic engineering of Saccharomyces cerevisiae for the production of n-butanol

<p>Abstract</p> <p>Background</p> <p>Increasing energy costs and environmental concerns have motivated engineering microbes for the production of "second generation" biofuels that have better properties than ethanol.</p> <p>Results and conclusion</p> <p><it>Saccharomyces cerevisiae </it>was engineered with an n-butanol biosynthetic pathway, in which isozymes from a number of different organisms (<it>S. cerevisiae</it>, <it>Escherichia coli</it>, <it>Clostridium beijerinckii</it>, and <it>Ralstonia eutropha</it>) were substituted for the Clostridial enzymes and their effect on n-butanol production was compared. By choosing the appropriate isozymes, we were able to improve production of n-butanol ten-fold to 2.5 mg/L. The most productive strains harbored the <it>C. beijerinckii </it>3-hydroxybutyryl-CoA dehydrogenase, which uses NADH as a co-factor, rather than the <it>R. eutropha </it>isozyme, which uses NADPH, and the acetoacetyl-CoA transferase from <it>S. cerevisiae </it>or <it>E. coli </it>rather than that from <it>R. eutropha</it>. Surprisingly, expression of the genes encoding the butyryl-CoA dehydrogenase from <it>C. beijerinckii </it>(<it>bcd </it>and <it>etfAB</it>) did not improve butanol production significantly as previously reported in <it>E. coli</it>. Using metabolite analysis, we were able to determine which steps in the n-butanol biosynthetic pathway were the most problematic and ripe for future improvement.</p

Brain-Specific Phosphorylation of MeCP2 Regulates Activity-Dependent Bdnf Transcription, Dendritic Growth, and Spine Maturation

Mutations or duplications in MECP2 cause Rett and Rett-like syndromes, neurodevelopmental disorders characterized by mental retardation, motor dysfunction, and autistic behaviors. MeCP2 is expressed in many mammalian tissues and functions as a global repressor of transcription; however, the molecular mechanisms by which MeCP2 dysfunction leads to the neural-specific phenotypes of RTT remain poorly understood. Here, we show that neuronal activity and subsequent calcium influx trigger the de novo phosphorylation of MeCP2 at serine 421 (S421) by a CaMKII-dependent mechanism. MeCP2 S421 phosphorylation is induced selectively in the brain in response to physiological stimuli. Significantly, we find that S421 phosphorylation controls the ability of MeCP2 to regulate dendritic patterning, spine morphogenesis, and the activity-dependent induction of Bdnf transcription. These findings suggest that, by triggering MeCP2 phosphorylation, neuronal activity regulates a program of gene expression that mediates nervous system maturation and that disruption of this process in individuals with mutations in MeCP2 may underlie the neural-specific pathology of RTT

Formation of Pt-Based Alloy Nanoparticles Assisted by Molybdenum Hexacarbonyl

We report on an optimized, scalable solution-phase synthetic procedure for the fabrication of fine-tuned monodisperse nanostructures (Pt(NiCo), PtNi and PtCo). The influence of different solute metal precursors and surfactants on the morphological evolution of homogeneous alloy nanoparticles (NPs) has been investigated. Molybdenum hexacarbonyl (Mo(CO)6) was used as the reductant. We demonstrate that this solution-based strategy results in uniform-sized NPs, the morphology of which can be manipulated by appropriate selection of surfactants and solute metal precursors. Co-surfactants (oleylamine, OAm, and hexadecylamine, HDA) enabled the development of a variety of high-index faceted NP morphologies with varying degrees of curvatures while pure OAm selectively produced octahedral NP morphologies. This Mo(CO)6-based synthetic protocol offers new avenues for the fabrication of multi-structured alloy NPs as high-performance electrocatalysts